Using app stores in different countries
I live in France and my IOS app store account is with the French app store. Is there any way I can download free apps from the USA store if they are not available from the French store?
No, you have to be in a country, and have a billing address in that country on your account, to use its store.
You can try requesting that they be added to the French store via http://www.apple.com/feedback/itunes.html, and/or by contacting the developer direct (there should be a link to their website on the app's description page in the store). Unless the developer grants Apple a license to sell the app in France then they won't be able to do so